dropped in water,plugged it comes on,unplugged goes out?

Pam, rice is a great first aid, but it will not prevent corrosion nor will it clean logic boards or repair batteries. The very first thing I would do, is to no longer charge it or turn it on. This will only increase the risk of failure due to short circuited components. Disassemble the Kindle using this teardown. Clean all the parts with isopropyl (90%+) alcohol. Visually check for any burned, charred or missing components, replace the battery, then reassemble your Kindle and re-evaluate. Hope this helps, good luck.